Isolation of polysacharides from sugar cane bagasse to obtain oligosacharides using enzymatic hydrolysis and gel permeation chromatography

Abstract

The aim of this project is to fill gaps and to develop research on isolation and characterization of enzymes with greater efficiency on hydrolysis of bagasse. The sugar cane bagasse will be first pretreated with alkaline hydrogen peroxide inside plastic bottles. The variables temperature, time, concentration of hydrogen peroxide and concentration of magnesium sulphate will be evaluated. The statistical analysis will provide the variables that influence the extraction of hemicellulose and cellulose from sugar cane bagasse. The responses yield of cellulose and hemicellulose, lignin extraction and the loss of cellulose and hemicellulose will be taken as responses of the experimental design. The hemicellulose obtained from sugar cane bagasse will be hydrolyzed by enzymes to produce oligosaccharides. In addition, the polysaccharide will be treated with Fe3 + reducing compounds in the presence or absence of ligninolytic enzymes, aimming the oxidation of residual lignin. The cellulignins produced from the experiments with hydrogen peroxide will be recovered with the objective to identify the factors that influence the subsequent enzymatic hydrolysis of the material. Thus, it is expected to evaluate the treatment conditions which allow removal of lignin and susceptibility to enzymatic hydrolysis. It will be assessed the treatment of celulignin with laccase, manganese peroxidase or metals and compounds of reducing Fe +3, for removing the residual lignin. The residual lignin presents in hemicellulose will also be removed using the same procedures used for celulignina. Complementary foccus will be given to the production of oligosaccharides, identification of alternative uses of the material pretreated with emphasis on improvement of pulp properties or enzymatic hydrolysis for ethanol from lignocellulosics. (AU)